A potential new dwarf planet has been discovered in the outer reaches of the solar system, and its existence poses the ...

As it orbits the sun once every 25,000 years, the celestial body 2017 OF201 travels beyond the Kuiper Belt into a region ...

The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system.

Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a highly ...

A new dwarf planet discovery in the outer solar system is challenging the long-standing theory of a hidden giant planet ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

OF201, a distant dwarf planet candidate with a rare orbit that questions the existence and stability of the Planet Nine theory.

A US-based trio hunting this elusive world has stumbled on what appears to be a new dwarf planet in the solar system's outer ...

A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

It is an evocative idea: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all ...